The Doctor tries to convince Sorenson to sacrifice himself for the rest of the crew but Salamar's attempt to deal with the situation causes their problems to multiply.
Quest roles:
Terry Walsh(Doran (uncredited)), Michael Wisher(Daleks (voice)), Prentis Hancock(Captain), Ewen Solon(Vishinsky), Frederick Jaeger(Professor Marius), Melvyn Bedford(Mummy)